The commercial web is now a teenager—it's been fifteen short years since Marc Andreessen released the Mosaic browser. To put this in perspective, television as a commercial medium reached its fifteenth birthday in 1956—the year Elvis Presley made his first appearance on national TV. National news broadcasts were still in their infancy, "As The World Turns" debuted as America's first half-hour soap opera, and "The Price Is Right" began its dominance of the game show genre. Commercial grade videotape recorders emerged, portable black and white television sets were introduced, and the first local color broadcast aired in Chicago.

Fifteen years after television's birth, the contours of the new medium were just emerging. The idea that this revolutionary new phenomenon—one busily reshaping the very fabric of society—might one day become just another application on a vast web of computers, well that idea wasn't exactly in vogue.

In the first four years of the Web 2.0 Summit, we've focused on our industry's challenges and opportunities, highlighting in particular the business models and leaders driving the Internet economy. But as we pondered the theme for this year, one clear signal has emerged: our conversation is no longer just about the Web. Now is the time to ask how the Web—its technologies, its values, and its culture—might be tapped to address the world's most pressing limits. Or put another way—and in the true spirit of the Internet entrepreneur—its most pressing opportunities.

As we convene the fifth annual Web 2.0 Summit, our world is fraught with problems that engineers might charitably classify as NP hard—from roiling financial markets to global warming, failing healthcare systems to intractable religious wars. In short, it seems as if many of our most complex systems are reaching their limits.

It strikes us that the Web might teach us new ways to address these limits. From harnessing collective intelligence to a bias toward open systems, the Web's greatest inventions are, at their core, social movements. To that end, we're expanding our program this year to include leaders in the fields of healthcare, genetics, finance, global business, and yes, even politics.

Increasingly, the leaders of the Internet economy are turning their attention to the world outside our industry. And conversely, the best minds of our generation are turning to the Web for solutions. At the fifth annual Web 2.0 Summit, we'll endeavor to bring these groups together.